text: Upon initial binding to the LRR region of FSHR, FSH reshapes its conformation to form a new pocket. FSHR then inserts its sulfotyrosine from the hinge loop  into the pockets and activates the 7-helical transmembrane domain.  This event leads to a transduction of the signal that activates the G protein that is bound to the receptor internally. With FSH  attached, the receptor shifts conformation and, thus, mechanically activates the G protein, which detaches from the receptor and activates the cAMP system.
  It is believed that a receptor molecule exists in a conformational equilibrium between active and inactive states. The binding of FSH to the receptor shifts the equilibrium between active and inactive receptors. FSH and FSH-agonists shift the equilibrium in favor of active states; FSH antagonists shift the equilibrium in favor of inactive states. For a cell to respond to FSH, only a small percentage (~1%) of receptor sites need to be activated.